Gui Minhai was snatched by the Chinese on 20 January
Photograph: Kin Cheung/AP

Swedish bookseller Gui Minhai was transporting secret documents to the Chinese capital when he was seized last month, a Communist party-run newspaper has claimed, as Stockholm hit back at the decision to parade its citizen before the Beijing-friendly press.

Gui, a publisher of racy tomes about Chinese politics whose stranger-than-fiction tale might have been lifted from one of his own titles, was snatched on 20 January as he attempted to reach Beijing with two Swedish diplomats.

On Friday, the 53-year-old Swede resurfaced at a detention centre in the eastern city of Ningbo, telling a group of handpicked reporters Sweden had tricked him into a botched bid to flee China.

“I fell for it,” Gui told journalists from Xinhua and the Global Times, two party-run outlets, as well as Hong Kong’s South China Morning Post, which faced criticism in 2016 for printing an apparently coerced interview with a young Chinese activist.

Xinhua, China’s official news agency, claimed Gui had “applied to authorities and asked to speak the truth before media”.

On Sunday, the Global Times, a state-run tabloid, published new details of the allegations against Gui, claiming he was suspected of involvement in “activities that jeopardise national security, including illegally offering national secrets and intelligence to overseas groups”. It alleged Gui had been in possession of “multiple documents containing national secrets” when he was detained.

An editorial in the same newspaper, which is known for its aggressive, nationalist tone, launched a scathing attack on Stockholm. “They tricked Gui into cooperating with their plan ... They wanted to arrange Gui’s ‘escape’ by breaking Chinese law,” it claimed, belittling Sweden as “a relatively small country in Northern Europe” that was trying “to demonstrate its diplomatic heroism by ‘saving the bookseller Gui Minhai’.”

Those efforts had failed “and the Swedish foreign ministry has ended up a laughingstock,” the newspaper boasted.

Gui’s daughter, Angela Gui, has rejected suggestions her father was in possession of any state secrets.

“He was in incommunicado detention for two years. So who would have told him these state secrets?” she told the Guardian last week.